1. Technical Field
The present disclosure relates to an electronic component device.
2. Description of the Related Art
With the recent development of an electronic device, a wiring board of an electronic component device for use in the electronic device has been required to be smaller in size and higher in performance. To meet the requirements, an electronic component built-in board in which an electronic component is built in a wiring board has been put into practical use.
In an example of such an electronic component built-in board, an upper wiring substrate is provided above a lower wiring substrate with the interposition of solder balls therebetween. The lower wiring substrate is mounted with a semiconductor chip. A space between the lower wiring substrate and the upper wiring substrate is filled with a sealing resin for sealing the semiconductor chip (see e.g., JP-A-2003-347722).
As will be described in a preliminary matter which will be described later, there is an electronic component device in which an upper wiring substrate is provided above a lower wiring substrate with the interposition of conductive balls therebetween, and the lower wiring substrate is mounted with a semiconductor chip. In such an electronic component device, the diameter of each of the conductive balls is required to be reduced in order to cope with the narrowed pitch of connection portions of the lower wiring substrate and the upper wiring substrate.
When the diameter of the conductive ball is reduced, the gap between the semiconductor chip and the upper wiring substrate is narrowed. For this reason, there is a likelihood that it may be not possible to well fill a space between the lower wring substrate and the upper wiring substrate with a sealing resin when the sealing resin is poured into the space.